Methods and systems for emergency call handling with position location over communication networks

ABSTRACT

Certain embodiments of the present disclosure relate to methods for handling an emergency call along with its position location in the WiMAX network, and for performing a handover of the emergency call for a multi-mode mobile station that supports multiple wireless standards.

CLAIM OF PRIORITY

The present Application for Patent claims benefit of Provisional PatentApplication Ser. No. 61/115,016 EMERGENCY CALL HANDLING WITH POSITIONLOCATION OVER WIMAX NETWORKS AND WIMAX/3G HANDOVER filed Nov. 14, 2008,and assigned to the assignee hereof and hereby expressly incorporated byreference herein.

TECHNICAL FIELD

Certain embodiments of the present disclosure generally relates towireless communication systems and more specifically to emergency calls.

SUMMARY

Certain embodiments provide a method of wireless communications. Themethod can include receiving a ranging request message from a mobilestation (MS) with an emergency call identification, setting up theemergency call, and determining a location of the emergency call basedon Global Positioning System (GPS) location information received fromthe MS.

Certain embodiments provide a method of wireless communications. Themethod can include requesting a handover during an emergency call,performing a Worldwide Interoperability for Microwave Access (WiMAX)handover procedure if the requested handover is from a serving basestation (BS) of the WiMAX network to a target BS of the WiMAX network,and performing a WiMAX handover procedure and a 3rd Generation/2ndGeneration (3G/2G) voice call handover procedure if the requestedhandover is from a serving BS of the WiMAX network to a target BS of the3G/2G network.

Certain embodiments provide an apparatus for wireless communications.The apparatus can include logic for receiving a ranging request messagefrom a MS with an emergency call identification, logic for setting upthe emergency call, and logic for determining a location of theemergency call based on Global Positioning System (GPS) locationinformation received from the MS.

Certain embodiments provide an apparatus for wireless communications.The apparatus can include logic for requesting a handover during anemergency call, logic for performing a Worldwide Interoperability forMicrowave Access (WiMAX) handover procedure if the requested handover isfrom a serving base station (BS) of the WiMAX network to a target BS ofthe WiMAX network, and logic for performing a WiMAX handover procedureand a 3rd Generation/2nd Generation (3G/2G) voice call handoverprocedure if the requested handover is from a serving BS of the WiMAXnetwork to a target BS of the 3G/2G network.

Certain embodiments provide an apparatus for wireless communications.The apparatus can include means for receiving a ranging request messagefrom a mobile station (MS) with an emergency call identification, meansfor setting up the emergency call, and means for determining a locationof the emergency call based on Global Positioning System (GPS) locationinformation received from the MS.

Certain embodiments provide an apparatus for wireless communications.The apparatus can include means for requesting a handover during anemergency call, means for performing a Worldwide Interoperability forMicrowave Access (WiMAX) handover procedure if the requested handover isfrom a serving base station (BS) of the WiMAX network to a target BS ofthe WiMAX network, and means for performing a WiMAX handover procedureand a 3rd Generation/2nd Generation (3G/2G) voice call handoverprocedure if the requested handover is from a serving BS of the WiMAXnetwork to a target BS of the 3G/2G network.

Certain embodiments provide a computer-program product for wirelesscommunications, including a computer readable medium having instructionsstored thereon, the instructions being executable by one or moreprocessors. The instructions can include instructions for receiving aranging request message from a mobile station (MS) with an emergencycall identification, instructions for setting up the emergency call, andinstructions for determining a location of the emergency call based onGlobal Positioning System (GPS) location information received from theMS.

Certain embodiments provide a computer-program product for wirelesscommunications, including a computer readable medium having instructionsstored thereon, the instructions being executable by one or moreprocessors. The instructions can include instructions for requesting ahandover during an emergency call, instructions for performing aWorldwide Interoperability for Microwave Access (WiMAX) handoverprocedure if the requested handover is from a serving base station (BS)of the WiMAX network to a target BS of the WiMAX network, andinstructions for performing a WiMAX handover procedure and a 3rdGeneration/2nd Generation (3G/2G) voice call handover procedure if therequested handover is from a serving BS of the WiMAX network to a targetBS of the 3G/2G network.

In certain embodiments, as presented in the summary paragraphs above andelsewhere within this disclosure, the MS can be configured for operationin a wireless communication system that supports an Institute ofElectronic and Electrical Engineers (IEEE) 802.16 standard.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to embodiments, someof which are illustrated in the appended drawings. It is to be noted,however, that the appended drawings illustrate only certain typicalembodiments of this disclosure and are therefore not to be consideredlimiting of its scope, for the description may admit to other equallyeffective embodiments.

FIG. 1 illustrates an example wireless communication system, inaccordance with certain embodiments of the present disclosure.

FIG. 2 illustrates various components that may be utilized in a wirelessdevice in accordance with certain embodiments of the present disclosure.

FIG. 3 illustrates an example transmitter and an example receiver thatmay be used within a wireless communication system in accordance withcertain embodiments of the present disclosure.

FIG. 4 illustrates example operations for setting up an emergency calland for determining its position location over the WiMAX network inaccordance with certain embodiments of the present disclosure.

FIG. 4A illustrates example components capable of performing theoperations illustrated in FIG. 4.

FIG. 5 illustrates example operations for performing a handover duringthe emergency call in accordance with certain embodiments of the presentdisclosure.

FIG. 5A illustrates example components capable of performing theoperations illustrated in FIG. 5.

FIG. 6 illustrates example operations for priority processing foremergency calls in accordance with certain embodiments of the presentdisclosure.

FIG. 6A illustrates example components capable of performing theoperations illustrated in FIG. 6.

DETAILED DESCRIPTION

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments.

In Worldwide Interoperability for Microwave Access (WiMAX) networks, itmay be required that emergency phone calls are handled while theirnetwork locations need to be fully determined. A position location foran emergency call may be mandatory. For example, the E911 emergency callwith mandatory position location is specified per Federal CommunicationsCommission (FCC) regulations. Furthermore, in multi-mode wirelesssystems that support more than one standard, it may be necessary tosupport a handover of the emergency call between, for example, the WiMAXnetwork and the 3rd Generation (3G) network.

Exemplary Wireless Communication System

The techniques described herein may be used for various broadbandwireless communication systems, including communication systems that arebased on an orthogonal multiplexing scheme. Examples of suchcommunication systems include Orthogonal Frequency Division MultipleAccess (OFDMA) systems, Single-Carrier Frequency Division MultipleAccess (SC-FDMA) systems, and so forth. An OFDMA system utilizesorthogonal frequency division multiplexing (OFDM), which is a modulationtechnique that partitions the overall system bandwidth into multipleorthogonal sub-carriers. These sub-carriers may also be called tones,bins, etc. With OFDM, each sub-carrier may be independently modulatedwith data. An SC-FDMA system may utilize interleaved FDMA (IFDMA) totransmit on sub-carriers that are distributed across the systembandwidth, localized FDMA (LFDMA) to transmit on a block of adjacentsub-carriers, or enhanced FDMA (EFDMA) to transmit on multiple blocks ofadjacent sub-carriers. In general, modulation symbols are sent in thefrequency domain with OFDM and in the time domain with SC-FDMA.

One specific example of a communication system based on an orthogonalmultiplexing scheme is a WiMAX system. WiMAX, which stands for theWorldwide Interoperability for Microwave Access, is a standards-basedbroadband wireless technology that provides high-throughput broadbandconnections over long distances. There are two main applications ofWiMAX today: fixed WiMAX and mobile WiMAX. Fixed WiMAX applications arepoint-to-multipoint, enabling broadband access to homes and businesses,for example. Mobile WiMAX offers the full mobility of cellular networksat broadband speeds.

IEEE 802.16x is an emerging standard organization to define an airinterface for fixed and mobile broadband wireless access (BWA) systems.These standards define at least four different physical layers (PHYs)and one medium access control (MAC) layer. The OFDM and OFDMA physicallayer of the four physical layers are the most popular in the fixed andmobile BWA areas respectively.

FIG. 1 illustrates an example of a wireless communication system 100 inwhich embodiments of the present disclosure may be employed. Thewireless communication system 100 may be a broadband wirelesscommunication system. The wireless communication system 100 may providecommunication for a number of cells 102, each of which is serviced by abase station 104. A base station 104 may be a fixed station thatcommunicates with user terminals 106. The base station 104 mayalternatively be referred to as an access point, a Node B or some otherterminology.

FIG. 1 depicts various user terminals 106 dispersed throughout thesystem 100. The user terminals 106 may be fixed (i.e., stationary) ormobile. The user terminals 106 may alternatively be referred to asremote stations, access terminals, terminals, subscriber units, mobilestations, stations, user equipment, etc. The user terminals 106 may bewireless devices, such as cellular phones, personal digital assistants(PDAs), handheld devices, wireless modems, laptop computers, personalcomputers, etc.

A variety of algorithms and methods may be used for transmissions in thewireless communication system 100 between the base stations 104 and theuser terminals 106. For example, signals may be sent and receivedbetween the base stations 104 and the user terminals 106 in accordancewith OFDM/OFDMA techniques. If this is the case, the wirelesscommunication system 100 may be referred to as an OFDM/OFDMA system(also noted herein as “OFDM/A”).

A communication link that facilitates transmission from a base station104 to a user terminal 106 may be referred to as a downlink (DL) 108,and a communication link that facilitates transmission from a userterminal 106 to a base station 104 may be referred to as an uplink (UL)110. Alternatively, a downlink 108 may be referred to as a forward linkor a forward channel, and an uplink 110 may be referred to as a reverselink or a reverse channel.

A cell 102 may be divided into multiple sectors 112. A sector 112 is aphysical coverage area within a cell 102. Base stations 104 within awireless communication system 100 may utilize antennas that concentratethe flow of power within a particular sector 112 of the cell 102. Suchantennas may be referred to as directional antennas.

FIG. 2 illustrates various components that may be utilized in a wirelessdevice 202 that may be employed within the wireless communication system100. The wireless device 202 is an example of a device that may beconfigured to implement the various methods described herein. Thewireless device 202 may be a base station 104 or a user terminal 106.

The wireless device 202 may include a processor 204 which controlsoperation of the wireless device 202. The processor 204 may also bereferred to as a central processing unit (CPU). Memory 206, which mayinclude both read-only memory (ROM) and random access memory (RAM),provides instructions and data to the processor 204. A portion of thememory 206 may also include non-volatile random access memory (NVRAM).The processor 204 typically performs logical and arithmetic operationsbased on program instructions stored within the memory 206. Theinstructions in the memory 206 may be executable to implement themethods described herein.

The wireless device 202 may also include a housing 208 that may includea transmitter 210 and a receiver 212 to allow transmission and receptionof data between the wireless device 202 and a remote location. Thetransmitter 210 and receiver 212 may be combined into a transceiver 214.An antenna 216 may be attached to the housing 208 and electricallycoupled to the transceiver 214. The wireless device 202 may also include(not shown) multiple transmitters, multiple receivers, multipletransceivers, and/or multiple antennas.

The wireless device 202 may also include a signal detector 218 that maybe used in an effort to detect and quantify the level of signalsreceived by the transceiver 214. The signal detector 218 may detect suchsignals as total energy, energy per subcarrier per symbol, powerspectral density and other signals. The wireless device 202 may alsoinclude a digital signal processor (DSP) 220 for use in processingsignals.

The various components of the wireless device 202 may be coupledtogether by a bus system 222, which may include a power bus, a controlsignal bus, and a status signal bus in addition to a data bus.

FIG. 3 illustrates an example of a transmitter 302 that may be usedwithin a wireless communication system 100 that utilizes OFDM/OFDMA.Portions of the transmitter 302 may be implemented in the transmitter210 of a wireless device 202. The transmitter 302 may be implemented ina base station 104 for transmitting data 306 to a user terminal 106 on adownlink 108. The transmitter 302 may also be implemented in a userterminal 106 for transmitting data 306 to a base station 104 on anuplink 1 10.

Data 306 to be transmitted is shown being provided as input to aserial-to-parallel (S/P) converter 308. The S/P converter 308 may splitthe transmission data into M parallel data streams 310.

The N parallel data streams 310 may then be provided as input to amapper 312. The mapper 312 may map the N parallel data streams 310 ontoN constellation points. The mapping may be done using some modulationconstellation, such as binary phase-shift keying (BPSK), quadraturephase-shift keying (QPSK), 8 phase-shift keying (8PSK), quadratureamplitude modulation (QAM), etc. Thus, the mapper 312 may output Nparallel symbol streams 316, each symbol stream 316 corresponding to oneof the N orthogonal subcarriers of the inverse fast Fourier transform(IFFT) 320. These N parallel symbol streams 316 are represented in thefrequency domain and may be converted into N parallel time domain samplestreams 318 by an IFFT component 320.

A brief note about terminology will now be provided. N parallelmodulations in the frequency domain are equal to N modulation symbols inthe frequency domain, which are equal to N mapping and N-point IFFT inthe frequency domain, which is equal to one (useful) OFDM symbol in thetime domain, which is equal to N samples in the time domain. One OFDMsymbol in the time domain, NS, is equal to NCP (the number of cyclicprefix (CP) samples per OFDM symbol)+N (the number of useful samples perOFDM symbol).

The N parallel time domain sample streams 318 may be converted into anOFDM/A symbol stream 322 by a parallel-to-serial (P/S) converter 324. Acyclic prefix insertion component 326 may insert a CP between successiveOFDM/A symbols in the OFDM/A symbol stream 322. The output of the CPinsertion component 326 may then be upconverted to a desired transmitfrequency band by a radio frequency (RF) front end 328. An antenna 330may then transmit the resulting signal 332.

FIG. 3 also illustrates an example of a receiver 304 that may be usedwithin a wireless device 202 that utilizes OFDM/OFDMA. Portions of thereceiver 304 may be implemented in the receiver 212 of a wireless device202. The receiver 304 may be implemented in a user terminal 106 forreceiving data 306 from a base station 104 on a downlink 108. Thereceiver 304 may also be implemented in a base station 104 for receivingdata 306 from a user terminal 106 on an uplink 110.

The transmitted signal 332 is shown traveling over a wireless channel334. When a signal 332′ is received by an antenna 330′, the receivedsignal 332′ may be downconverted to a baseband signal by an RF front end328′. A CP removal component 326′ may then remove the CP that wasinserted between OFDM/OFDMA symbols by the CP insertion component 326.

The output of the CP removal component 326′ may be provided to an S/Pconverter 324′. The S/P converter 324′ may divide the OFDM/OFDMA symbolstream 322′ into the N parallel time-domain symbol streams 318′, each ofwhich corresponds to one of the N orthogonal subcarriers. A fast Fouriertransform (FFT) component 320′ may convert the N parallel time-domainsymbol streams 318′ into the frequency domain and output N parallelfrequency-domain symbol streams 316′.

A demapper 312′ may perform the inverse of the symbol mapping operationthat was performed by the mapper 312 thereby outputting N parallel datastreams 310′. A P/S converter 308′ may combine the N parallel datastreams 310′ into a single data stream 306′. Ideally, this data stream306′ corresponds to the data 306 that was provided as input to thetransmitter 302. Note that elements 308′, 310′, 312′, 316′, 320′, 318′and 324′ may all be found in a baseband processor 340′.

WiMAX systems, such as the one illustrated in FIG. 1, may be required tohandle emergency calls, while network locations of emergency calls mayneed to be fully determined. Knowledge of location of an emergency callmay be mandatory per FCC regulations, such as it is mandatory for theE911 emergency call. Furthermore, in multi-mode systems that supportmultiple wireless standards, handovers of emergency calls may benecessary. It may be required, e.g., to perform a handover of theemergency call between the WiMAX network and the 3rd Generation/2ndGeneration (3G/2G) network for a multi-mode mobile station. Certainembodiments of the present disclosure relate to methods for handling theemergency call along with its position location in the WiMAX network, aswell as to methods for performing a handover of the emergency call fromto a base station that supports the same or different standards.

Exemplary Emergency Call Set-up and Location Update

FIG. 4 illustrates example operations 400 for setting up an emergencycall and for determining position location of an MS placing the callover the WiMAX network. The operations begin, at 410, with a mobilestation (MS) sending a ranging request (RNG-REQ) message to a basestation (BS) with an indication about the emergency call. The emergencycall may be indicated using a special bit within a Ranging PurposeIndicator field of the RNG-REQ message.

At 420, the emergency call may be set up by the serving BS. For certainembodiments of the present disclosure the serving BS may initiate theemergency call over a Voice over Internet Protocol (VoIP). If the servedMS is in an idle mode, then the BS may page the MS before setting up theemergency call. On the other hand, if the MS have already used sometraffic connections, then the BS may send a Dynamic Service Addition(DSA) message to the MS in order to initiate the emergency call.

For certain embodiments of the present disclosure, the MS may initiatethe emergency call through a regular data call, but with a new Qualityof Service (QoS) emergency call parameter. For certain embodiments ofthe present disclosure, the MS may initiate the emergency call over theVoIP after a ranging procedure with the serving BS. An average timespent in the ranging procedure for emergency calls may need to besmaller than for regular calls. For example, the average waiting timemay be decreased if the MS is allowed to utilize multiple TransmissionOpportunities (TOs) within the same frame or within adjacent frames inorder to increase a probability of successful ranging with the servingBS. The number of TOs may be adjusted based upon a current rangingtraffic condition of the serving BS. The probability of successfulranging with the serving BS for the emergency call may be also increasedif a transmission power for sending Code Division Multiple Access (CDMA)ranging codes is increased by some emergency weight factor that may bedetermined, for example, by a network operator.

In order to speed up the emergency call procedure, the setup of theemergency call may bypass an authentication procedure. Furthermore, thesetup for the emergency call may not require the MS to be registeredwith any BS or even to be provisioned (e.g., in the case of the firstpurchase of the MS without signing up with any provider, in the case ofloss or corruption of provisioning information, etc). The authenticationprocedure may be re-performed once the emergency service between anemergency call center and the MS is established. The purpose ofre-performing the authentication procedure may be to upgrade a basicemergency service application (e.g., a voice call or a simple textmessage) to an advanced emergency service application that requires alarger bandwidth (e.g., an emergency application that simultaneouslysupports both voice and data).

Following the emergency call setup or in the same time with theemergency call setup, the serving BS may receive, at 430, GlobalPositioning System (GPS) location information from the MS. Based on thereceived GPS information, the BS may determine a network location of theemergency call. The BS may send a GPS location request either once orperiodically, and the MS may respond with its GPS location information.Once the GPS information is received at the BS, the BS may also forwardthis information to the emergency call center.

As an alternative to (or in addition to) step 430, the MS may send theGPS location information periodically to the BS following the rangingprocedure with the emergency call indication or after the emergency callsetup. The BS may receive the GPS information and may send thisinformation to the emergency call center. For certain embodiments of thepresent disclosure, the MS or the BS can set up the emergency GPS for aregular data call, and the emergency call center may exchange theemergency GPS information using an existing protocol over the WiMAXspecial data call or over the WiMAX regular data call. At 440, theserving BS may communicate over the WiMAX network with the MS using theestablished emergency call, while the location of the emergency call isknown to the BS and to the emergency call center.

Exemplary Emergency Call Handover

FIG. 5 illustrates example operations for performing a handover duringan emergency VoIP call. The operations begin, at 510, with a multi-modemobile station (MS) requesting a handover during a WiMAX emergency call.If the multimode MS needs to handover the emergency VoIP call from aserving WiMAX base station (BS) to a target WiMAX BS (which can bedecided at 520), then the MS may apply a WiMAX handover procedure forperforming a handover, at 540. Preceding the WiMAX handover procedure,at 530, the MS may release some services different than the emergencycall service (e.g., a simultaneous VoIP call, an internet protocoltelevision (IPTV) service, an internet browsing service, an e-mailservice, etc) if the MS cannot handover all existing services.

On the other hand, if the multimode MS needs to handover the emergencyVoIP call from a serving WiMAX BS to a target 3G/2G BS (which can bedecided at 520), then the MS may apply the WiMAX handover procedurealong with the 3G/2G voice call handover procedure for performing ahandover, at 560. Preceding the handover of the emergency call from theserving WiMAX BS to the target 3G/2G BS, at 550, the MS may release someservices different than the emergency call service (e.g., simultaneousVoIP call, IPTV service, internet-browsing service, email service, etc)if the MS cannot handover all existing services from one network toanother.

Exemplary Priority Processing for Emergency Calls

For certain embodiments of the present disclosure, a serving BS may takemeasures to allow emergency calls to be prioritized. FIG. 6 illustratesexample operations for priority processing applied in the case ofemergency calls.

At 610, the BS may reserve a special range of CDMA codes to a served MSin order to perform ranging for the emergency call, and a randomselection after collision may be utilized. If the MS cannot performsuccessful ranging by using the special ranging CDMA codes, then the MSmay use the existing initial or handover ranging codes in order toperform ranging. In certain embodiments, instead of using a randomnumber generator to select the CDMA code, some CDMA code may be reservedfor an emergency call. In this way, the BS may get an early alert that acoming CDMA ranging code traffic from the MS could be related to theemergency call.

At 620, the BS may process Media Access Control (MAC) managementmessages for setting up the emergency call with a higher priority thanfor regular messages. Examples of MAC management messages for theemergency call setup are: a Paging Advertising (PAG-ADV) message, aRange Request (RNG-REQ) message, a Range Response (RNG-RSP) message, aDynamic Service Addition Request (DSA-REQ) message, a Dynamic ServiceAddition Response (DSA-RSP) message, a Dynamic Service AdditionAcknowledgement (DSA-ACK) message, etc.

At 630, the BS may allocate a dedicated data grant for the MS forsending the next expected MAC management message. For example, afterreceiving the RNG-RSP message, the BS may allocate the data grant forthe MS for sending the DSA-REQ message, which may avoid acontention-based bandwidth request procedure.

At 640, the admission control of the BS may admit emergency calls withhigher priority than regular calls. If the serving BS does not haveenough bandwidth for all existing service flows at the MS, then someservice flow(s) may be released. Moreover, at 650, a target BS mayrelease some existing regular service flow(s) if there is not enoughbandwidth during the handover of the emergency call from the currentlyserving BS to the target BS. At 660, data schedulers of the BS and ofthe MS may schedule data packets of the emergency call with a higherpriority than data packets of other regular service flows.

The various operations of methods described above may be performed byvarious hardware and/or software component(s) and/or module(s)corresponding to means-plus-function blocks illustrated in the Figures.For example, blocks 410-440 illustrated in FIG. 4 correspond tomeans-plus-function blocks 410A-440A illustrated in FIG. 4A. Similarly,blocks 510-560 illustrated in FIG. 5 correspond to means-plus-functionblocks 510A-560A illustrated in FIG. 5A. Similarly, blocks 610-660illustrated in FIG. 6 correspond to means-plus-function blocks 610A-660Aillustrated in FIG. 6A. More generally, where there are methodsillustrated in Figures having corresponding counterpartmeans-plus-function Figures, the operation blocks correspond tomeans-plus-function blocks with similar numbering.

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array signal (FPGA) or other programmable logic device(PLD), discrete gate or transistor logic, discrete hardware componentsor any combination thereof designed to perform the functions describedherein. A general purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described herein may be embodieddirectly in hardware, in a software module executed by a processor, orin a combination of the two. A software module may reside in any form ofstorage medium that is known in the art. Some examples of storage mediathat may be used include random access memory (RAM), read only memory(ROM), flash memory, EPROM memory, EEPROM memory, registers, a harddisk, a removable disk, a CD-ROM and so forth. A software module maycomprise a single instruction, or many instructions, and may bedistributed over several different code segments, among differentprograms, and across multiple storage media. A storage medium may becoupled to a processor such that the processor can read informationfrom, and write information to, the storage medium. In the alternative,the storage medium may be integral to the processor.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

The functions described may be implemented in hardware, software,firmware or any combination thereof. If implemented in software, thefunctions may be stored as one or more instructions on acomputer-readable medium. A storage media may be any available mediathat can be accessed by a computer. By way of example, and notlimitation, such computer-readable media can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code in the form of instructions or datastructures and that can be accessed by a computer. Disk and disc, asused herein, include compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers.

Software or instructions may also be transmitted over a transmissionmedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition oftransmission medium.

Further, it should be appreciated that modules and/or other appropriatemeans for performing the methods and techniques described herein can bedownloaded and/or otherwise obtained by a user terminal and/or basestation as applicable. For example, such a device can be coupled to aserver to facilitate the transfer of means for performing the methodsdescribed herein. Alternatively, various methods described herein can beprovided via storage means (e.g., RAM, ROM, a physical storage mediumsuch as a compact disc (CD) or floppy disk, etc.), such that a userterminal and/or base station can obtain the various methods uponcoupling or providing the storage means to the device. Moreover, anyother suitable technique for providing the methods and techniquesdescribed herein to a device can be utilized.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the methods and apparatus described above without departingfrom the scope of the claims.

What is claimed is:
 1. A method of wireless communications by a mobilestation (MS), comprising: transmitting a ranging request messagecontaining an emergency call identification provided in a rangingpurpose indicator field to set up, with a first base station, anemergency call associated with the emergency call identification;transmitting Global Positioning System (GPS) location information to thefirst base station for use in determining a location of the emergencycall; performing a ranging procedure for the emergency call by sendingCode Division Multiple Access ranging codes with higher transmissionpower in the ranging procedure for the emergency call than in a rangingprocedure for a non-emergency call, wherein the ranging procedure forthe emergency call is performed faster than the ranging procedure forthe non-emergency call; receiving instructions to perform a handover ofthe emergency call from the first base station to a second base station;and when there are not enough bandwidth resources to handover allexisting services, releasing, before the handover, a service differentfrom the emergency call.
 2. The method of claim 1 further comprising:receiving, from the first base station, a paging message before settingup the emergency call if the MS is in an idle mode; and receiving, fromthe first base station, a Dynamic Service Addition (DSA) if the MS doesnot have a traffic connection.
 3. The method of claim 1, furthercomprising: initiating the emergency call through a data call with aQuality of Service (QoS) emergency call parameter.
 4. The method ofclaim 1, wherein setting up the emergency call bypasses anauthentication procedure.
 5. The method of claim 1, wherein the MS isnot registered with any serving base station.
 6. The method of claim 1,further comprising: receiving, from the first base station, an initialGPS location request; and receiving, from the first base station,periodic GPS location requests.
 7. The method of claim 1 furthercomprising: transmitting GPS location information to the first basestation after performing the ranging procedure with the first basestation.
 8. The method of claim 1 further comprising: using a specialrange of Code Division Multiple Access codes when performing the rangingprocedure for the emergency call; transmitting Media Access Control(MAC) management messages for setting up the emergency call with ahigher priority than for processing regular messages; using a dedicateddata grant to send a next expected MAC management message, the dedicateddata grant being allocated by the first base station; and receiving datapackets of the emergency call, wherein the data packets of the emergencycall are scheduled with a higher priority than data packets of otherregular service flows.
 9. The method of claim 1, wherein the emergencycall is admitted with a higher priority than the non-emergency call. 10.An apparatus of wireless communications, comprising: logic fortransmitting a ranging request message containing an emergency callidentification provided in a ranging purpose indicator field to set up,with a first base station, an emergency call associated with theemergency call identification; logic for transmitting Global PositioningSystem (GPS) location information to the first base station for use indetermining a location of the emergency call; logic for performing aranging procedure for the emergency call by sending Code DivisionMultiple Access ranging codes with higher transmission power in theranging procedure for the emergency call than in a ranging procedure fora non-emergency call, wherein the ranging procedure for the emergencycall is performed faster than the ranging procedure for thenon-emergency call; logic for receiving instructions to perform ahandover of the emergency call from the first base station to a secondbase station; and logic for releasing, before the handover, a servicedifferent from the emergency call when there are not enough bandwidthresources to handover all existing services.
 11. The apparatus of claim10 further comprising: logic for receiving, from the first base station,a paging message before setting up the emergency call if the apparatusis in an idle mode; and logic for receiving, from the first basestation, a Dynamic Service Addition (DSA) if the apparatus does not havea traffic connection.
 12. The apparatus of claim 10, further comprising:logic for initiating the emergency call through a data call with aQuality of Service (QoS) emergency call parameter.
 13. The apparatus ofclaim 10, wherein the logic for setting up the emergency call compriseslogic for bypassing an authentication procedure.
 14. The apparatus ofclaim 10, wherein the apparatus is not registered with any serving basestation.
 15. The apparatus of claim 10, further comprising: logic forreceiving, from the first base station, an initial GPS location request;and logic for receiving, from the first base station, periodic GPSlocation requests.
 16. The apparatus of claim 10 further comprising:logic for transmitting GPS location information after performing theranging procedure with the first base station.
 17. The apparatus ofclaim 10 further comprising: logic for using a special range of CodeDivision Multiple Access (CDMA) codes when performing the rangingprocedure for the emergency call; logic for transmitting Media AccessControl (MAC) management messages for setting up the emergency call witha higher priority than for processing regular messages; logic for usinga dedicated data grant to send a next expected MAC management message,the dedicated data grant being allocated by the first base station; andlogic for receiving data packets of the emergency call, wherein the datapackets of the emergency call are scheduled with a higher priority thandata packets of other regular service flows.
 18. The apparatus of claim10, wherein the emergency call is admitted with a higher priority thanthe non-emergency call.
 19. An apparatus of wireless communications,comprising: means for transmitting a ranging request message containingan emergency call identification provided in a ranging purpose indicatorfield to set up, with a first base station, an emergency call associatedwith the emergency call identification; means for transmitting GlobalPositioning System (GPS) location information to the first base stationfor use in determining a location of the emergency call; means forperforming a ranging procedure for the emergency call by sending CodeDivision Multiple Access ranging codes with higher transmission power inthe ranging procedure for the emergency call than in a ranging procedurefor a non-emergency call, wherein the ranging procedure for theemergency call is performed faster than the ranging procedure for thenon-emergency call; means for receiving instructions to perform ahandover of the emergency call from the first base station to a secondbase station; and means for releasing, before the handover, a servicedifferent from the emergency call when there are not enough bandwidthresources to handover all existing services.
 20. The apparatus of claim19 further comprising: means for receiving, from the first base station,a paging message before setting up the emergency call if the apparatusis in an idle mode; and means for receiving, from the first basestation, a Dynamic Service Addition (DSA) if the apparatus does not havea traffic connection.
 21. The apparatus of claim 19, further comprising:means for initiating the emergency call through a data call with aQuality of Service (QoS) emergency call parameter.
 22. The apparatus ofclaim 19, wherein the means for setting up the emergency call comprisesmeans for bypassing an authentication procedure.
 23. The apparatus ofclaim 19, wherein the apparatus is not registered with any serving basestation.
 24. The apparatus of claim 19, further comprising: means forreceiving, from the first base station, an initial GPS location request;and means for sending receiving, from the first base station, periodicGPS location requests.
 25. The apparatus of claim 19 further comprising:means for transmitting GPS location information to the first basestation after performing the ranging procedure with the first basestation.
 26. The apparatus of claim 19 further comprising: means forusing a special range of Code Division Multiple Access (CDMA) codes whenperforming the ranging procedure for the emergency call; means fortransmitting Media Access Control (MAC) management messages for settingup the emergency call with a higher priority than for processing regularmessages; means for using a dedicated data grant for the MS to send anext expected MAC management message, the dedicated data grant beingallocated by the first base station; and means for receiving datapackets of the emergency call, wherein the data packets of the emergencycall are scheduled with a higher priority than data packets of otherregular service flows.
 27. The apparatus of claim 19, wherein theemergency call is admitted with a higher priority than the non-emergencycall.
 28. A computer-program storage apparatus of wirelesscommunications, comprising a memory having instructions stored thereon,the instructions being executable by one or more processors of a mobilestation (MS) and the instructions comprising: instructions fortransmitting a ranging request message containing an emergency callidentification provided in a ranging purpose indicator field to set up,with a first base station, an emergency call associated with theemergency call identification; instructions for transmitting GlobalPositioning System (GPS) location information to the first base stationfor use in determining a location of the emergency call; instructionsfor performing a ranging procedure for the emergency call by sendingCode Division Multiple Access ranging codes with higher transmissionpower in the ranging procedure for the emergency call than in a rangingprocedure for a non-emergency call, wherein the ranging procedure forthe emergency call is performed faster than the ranging procedure forthe non-emergency call; instructions for receiving a handover message toperform a handover of the emergency call from the first base station toa second base station; and instructions for releasing, before thehandover, a service different from the emergency call when there are notenough bandwidth resources to handover all existing services.
 29. Thecomputer-program storage apparatus of claim 28, wherein the instructionsfurther comprise: instructions for receiving, from the first basestation, a paging message before setting up the emergency call if the MSis in an idle mode; and instructions for receiving, from the first basestation, a Dynamic Service Addition (DSA) if the MS does not have atraffic connection.
 30. The computer-program storage apparatus of claim28, wherein the instructions further comprise: instructions forinitiating the emergency call through a data call with a Quality ofService (QoS) emergency call parameter.
 31. The computer-program storageapparatus of claim 28, wherein the instructions for setting up theemergency call comprise instructions for bypassing an authenticationprocedure.
 32. The computer-program storage apparatus of claim 28,wherein the MS is not registered with any serving base station.
 33. Thecomputer-program storage apparatus of claim 28, wherein the instructionsfurther comprise: instructions for receiving, from the first basestation, an initial GPS location request; and instructions forreceiving, from the first base station, periodic GPS location requests.34. The computer-program storage apparatus of claim 28, wherein theinstructions further comprise: instructions for transmitting GPSlocation information to the first base station after performing theranging procedure with the first base station.
 35. The computer-programstorage apparatus of claim 28, wherein the instructions furthercomprise: instructions for using a special range of Code DivisionMultiple Access (CDMA) codes when performing the ranging procedure forthe emergency call; instructions for transmitting Media Access Control(MAC) management messages for setting up the emergency call with ahigher priority than for processing regular messages; instructions forusing a dedicated data grant to send a next expected MAC managementmessage, the dedicated data grant being allocated by the first basestation; and instructions for receiving data packets of the emergencycall, wherein the data packets of the emergency call are scheduled witha higher priority than data packets of other regular service flows. 36.The computer-program storage apparatus of claim 28, wherein theemergency call is admitted with a higher priority than the non-emergencycall.